Galaxy 55 Tdi Squealing under load

[mushdy]

Hi there, I've got a 55 plate Galaxy Ghia 150 which in the last couple of weeks has developed an annoying squealing sound. It is only there when I accelerate and more apparent in lower gears. The sound changes pitch depending on how hard the accelerator is pressed. If you lift off the gas it disappears altogether. Have tried spraying the auxiliary belt with WD40 but this has no effect. Wondering whether it could be turbo related? Have had a quick listen under the bonnet but can't really hear anything unless the engine is loaded up. The change in pitch isn't progressive either, seems to jump from low to high which makes me think it's more likely to be bearings than belts or leaks....any ideas welcome.

[Chrispb]

Hello and  to the forum

Squealing noises (not the normal spooling noise) can be worrying.
Would advise checking the turbo shaft for excess movement (axially and radially), there is always am amount of play in the shaft ( don't know the specs but the blades should not contact the housing, at a guess I would say .020 thou radial and less for axial, contact a specialist for exact details

[Mirez]

Personally, before I stripped anything down I'd pop the aux belt off and go for a short drive (you'll have no power steering, A/C or alternator!) however you'll rule out all the pulleys, idlers and tensioner in one go.

[mushdy]

Thanks very much chrispb and Mirez for your replies, will definitely try taking the belt off to remove all of the auxiliaries first, hopefully I can get that done over the weekend and like you've said that'll rule out quite a lot of items. Failing that I guess I'll have to investigate the turbo  Hope it's something to do with the aux belt! Will let you know how I get on. Thanks again.

[mushdy]

Just a quick update, took the aux belt off and the squeal was still there. Visited my local independent vw specialist on friday and managed to get the noise whilst revving in situ. He reckoned it could be a boost leak as it was coming from the top right hand side of the engine so I've had a look at the pipes around that area but they all seem okay. I've booked it in for a boost test now so hopefully that will show a split somewhere or maybe some issue with the turbo. My only other thought is clutch....anyone know if they ever develop squealing sounds?

[Mirez]

Where the intercooler pipe enters the EGR is a well known "leak" spot across the PD range of engines (silly C clip thing is all that holds it in) so might be worth a look there

[mushdy]

Hi mirez, yes had a look at that, I took the egr valve off to clean while I was at it and was totally flabbergasted with the state of it. When I seperated the egr from the inlet manifold the flow area was literally half of the size of the pipe due to the amount of crud that had built up in the valve. Gave it a good clean and it seems to be idling a bit better now. Think I'm gonna blank it off. When I removed that rubber pipe that goes into the egr I noticed that there was a rubber seal on one end that fits into the body of the egr . It didn't seem a very tight fit so I thought I might try to wrap the joint with some tape to see if it helps with the squeal. Gonna give it a go in the morning.

[mushdy]

Well, taping up the joint between the right angle flexi inlet pipe and egr valve made no difference at all and I can't see any splits or cracks in the flexi or hard plastic section of pipe either  . I'm pretty sure though that the sound is coming from the area around that pipe and the tandem fuel pump. Has anyone ever heard of bushes or bearings failing in the tandem pump and causing squeaking / squealing noises on acceleration?

[Chrispb]

Try disconnecting the turbo actuator hose temporarily, this will stop the turbo creating boost pressure and reduce noise from the turbo.
You will find the hose clipped to the side of the turbo inlet pipe, if you follow the pipe to where It's clipped to the inner wing there is a joint there to disconnect easily.

[mushdy]

Hi chrispb, thanks for the advice, will try it later. Just to confirm, the turbo inlet pipe is the large diameter metal pipe that you can see when you look down between the air cleaner housing and the aux belt on the left side of the engine bay? What sort of size is the actuator hose and is the joint best accessed from underneath?

[Chrispb]

See pic below, as you can see it's directly in front of the brake master cylinder, easier to disconnect here than getting underneath[attachimg=1]

[mushdy]

that's excellent, thanks very much chris, will have a go tomorrow 

[mushdy]

Hi Chris, had a result today, took your advice and disconnected the turbo actuator hose, NO squealing!! No power either but the squeal had definitely gone even when I floored the throttle. I'm assuming that the problem is either the turbo itself or the associated pipework and clips. When I connected it back up the noise was there straight away. Next job is to try and get the MAP pipe off because the sound seems to be coming from that area, maybe one of the joints closer to the intercooler. Will let you know if I find anything. Thanks again 

[Chrispb]

If you cant find anything wrong with the pipework I think you need to check for excess play in the turbine /compressor shaft, you will need to remove the exhaust downpipe and the plastic inlet tube to do this.

[mushdy]

Righto, Chris will do. I'm keeping my fingers crossed it's pipework at the moment, not fancying a bill for a turbo rebuild..... 

[mushdy]

Think I'm gonna have to bite the bullet and get the turbo off Chris. Took the MAP pipe off today from the EGR to where it joins to the intercooler but couldn't see any signs of splits or cracks. I also had a good look at the pipe running from the turbo to the intercooler but again it seemed fine. Do you think ramps will do for getting access to the turbo shaft or should I try to get it on a lift? Is removing the exhaust downpipe a DIY job? I guess I'll need to soak the bolts for a couple of hours first....just wondering when I took the turbo actuator pipe off, does that prevent the turbo from spooling up? and therefore if there is play in the shaft am I correct in assuming that I wouldn't hear the squeal because the actuator is disconnected?

[Chrispb]

Ramps are best for diy, the nuts on the exhaust will be rusty but give them a soak overnight.
Disconnecting the actuator doesn't stop the turbo completely, it will spool up at a lower rpm but the turbo vanes will stay closed so no load is placed on the shaft.

[mushdy]

Thanks Chris, that makes sense. Where I was thinking the sound was coming from the area around the map pipe it was probably the turbo noise being carried through the pipework to that area, that would explain why it's so difficult to pinpoint the source of the noise. New bottle of Plusgas on the way home!!

[Chrispb]

Blimey Plusgas, you must be an old boy too, do they still make that stuff.

[mushdy]

Lol!! not that old just yet, just going back to my days as a spotty 16 year old pulling my first mini to bits!! 

[mushdy]

Hi guys, well after 4 weeks of removing various bits of pipework and belts I had failed to find this damn squeal! Took your advice Chris and removed the plastic inlet tube to check out play in the compressor shaft. There did appear to be some so I thought it best to remove the whole assembly, so EGR, inlet manifold and exhaust manifold/turbo are now off the engine. At this point I'd just like to say a huge thank you to chrispb and Mirez for providing such an excellent resource of tutorials in the knowledge base. I couldn't have done the job without that, so many thanks. So the turbo is now on the bench and there is obvious play in the shaft. If I put some lateral pressure on the shaft from the exhaust side, I can get the veins on the inlet side to drag on the casing and you can actually feel the shaft move from side to side.
[attachimg=1]
[attachimg=2]
If you look at the veins at 9o'clock and 3o'clock you can see the differences in clearance between the veins and the inner walls of the casing as I apply pressure to the other end of the shaft. Not sure how to measure these accurately but I'm sure it shouldn't be like that! So I reckon I might have found the cause of the squeal but the big question is, do I have to buy a new turbo or can anyone recommend a good rebuilding service? I was expecting to find a Garrett turbo but the only brand I can see is KKK Germany, part number is 03G 253 014 C. It is a bit of a relief to have found something which may be causing the problem but on the other hand quite worrying as to how much it might cost to fix!!

[mushdy]

Just found it's a Borg Warner....

[mushdy]

Hi guys, thought I'd clean up some of the bits I've taken off recently whilst mulling over whether I want to spend Ã,£600 on a new turbo  when I found this:
[attachimg=1]
Now maybe I'm clutching at straws but could this be an air leak in the inlet manifold gasket which is causing my squeal?? I've been back and forth my local vw/audi specialist half a dozen times with this problem and he's always maintained that it's an air leak, although we've been unable to find anything. Also, I spoke to a local Subaru specialist about the turbo and he said that there is always play in the compressor shaft as it is designed to run on a bed of oil. I've had a really good look inside the compressor housing and I can't see any signs of scoring or any kind of wear or damage to the impellors. I'm a bit stumped as to what to do  . Thinking of cleaning everything up, giving the turbo a dose of Innotec and fitting a new gasket set to see if that sorts it. Any thoughts appreciated. Mushdy.

[Mirez]

Think thats what I'd do.

Yes the impellor should have some float and its a fine line between normal and excessive, however since you cant see any scoring then its unlikely to be touching.

The manifold would be a great place to start as it's clearly been leeking from there and thats a high pressure point so the air would be whistling out potentially quite noisily

[mushdy]

Thanks Mirez. Even if it doesn't work, think I'd like to explore all possibilities before shelling out on a turbo.

[mushdy]

Well, I'm very happy to report that the squeal is no more!!
Didn't replace the turbo in the end, just gave it a real good clean with an Innotec kit. Replaced inlet manifold gasket, exhaust manifold gasket and turbo to front pipe gasket. Also gave all the manifold faces a  good clean up as best I could. A thorough clean of the inlet manifold and EGR valve and I've also blanked the EGR valve off and plugged the vacuum pipe. New PD oil and filter and she's as sweet as a nut. Happy days 

[Mirez]

I think the word is "Yeee-haaa"

Good work mate, always nice when it's a cheap fix!

[Chrispb]

 

So it would appear that it wasn't a mechanical noise but more a whistle/escaping air type noise!!

Well done

[mushdy]

Thanks guys, yep really happy with the result, chuffed to bits  just given her a celebratory wash and wax too! Thanks again for the help and advice